How would you fill in brass on a pitted brass piece - brazing?

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Maybe a bit unusual for this forum, I'm looking for a way to add material to pitted areas of a brass instrument, in this case the valve casing. The ultimate goal is to build up a small amount of material to fill in the pitted areas to then grind it down flush to the surface in preparation for silver plating. The material is approx 2 mm thick and the method used needs to not burn through. How would you do something like that?Thanks.
Reply:Brazing but you'd really have to watch your heat.
Reply:Most instruments are silver soldered. Some may be soft soldered. I'd silver solder the pits. Your plater may have experience and may suggest specific alloys. In any event you'll need a fine torch to keep the heat in check. I've never soldered an instrument so your mileage may vary.
Reply:Does silver plating work on silver solder or even soft solder?
Reply:Originally Posted by G-sonDoes silver plating work on silver solder or even soft solder?
Reply:Well, then you're going to be brazing, or rather welding as the bronze brazing rod (technically closer to being brass as it's mainly made from copper and zinc) has just about the same melting point as the brass you are working on - the base metal will melt, and burnthrough may very well be an issue. I suggested silver/soft solder as they melt long before the brass base metal, making burnthrough impossible. I'm sure it can be done, although I'd recommend trying that on something that's already junk, not a repair that needs to be successfull.
Reply:Originally Posted by Robert PProbably but I'd like to find out how to add brass to the pitted areas in case there are other horns where I might want to use a lacquer coating, i.e. where the color of the underlying material would matter.
Reply:did you talk to the folks that do your plating ?They can fill pits with repeated rounds of copper plating before they do the shiny outer layers.
Reply:Originally Posted by 12345678910did you talk to the folks that do your plating ?They can fill pits with repeated rounds of copper plating before they do the shiny outer layers.
Reply:Originally Posted by forhireThe trick may be finding a alloy that matches the original brass color. There are some silver solders that are color matched for yellow and red brass. Jewelry suppliers may be a good place to start. Quick google search returned a few.https://www.riogrande.com/Product/br...r-20-ga/132201
Reply:Originally Posted by forhireThe trick may be finding a alloy that matches the original brass color. There are some silver solders that are color matched for yellow and red brass. Jewelry suppliers may be a good place to start. Quick google search returned a few.https://www.riogrande.com/Product/br...r-20-ga/132201
Reply:Originally Posted by Robert PNo doubt but it would be less expensive to give them a horn that requires no other prep. I'm also looking into DIY spot-plating.
Reply:Originally Posted by Robert PWill this solder flow and fill an area - i.e. the pitted spots - without having to bond tow pieces of metal together?
Reply:Originally Posted by 12345678910Before you do anything, I'd ask what they recommend.Are you sure that plating will stick to solder ?What instrument ?Like that valve case on a trumpet ?That material if very thin and needs a close fit to the sliding parts.I'd not want to add heat unless you were an expert at it.It's unbelievable how metal moves with heat.
Reply:Originally Posted by Robert PYes, the valve casing on a trumpet. Certain spots tend to suffer friction and chemical wear over time and then the exposed brass gets pitted for the same reason.You can solder onto silver plate so clearly the two will bond. I'll check further but I'm pretty sure you can plate over solder as long as the surface is correctly prep'd.
Reply:The jewelers use a silver paste then heat to set, check jewelery supply houses